From: Stephen Hemminger <stephen@networkplumber.org>
To: Jerin Jacob <jerinjacobk@gmail.com>
Cc: dev@dpdk.org, Pavan Nikhilesh <pbhagavatula@marvell.com>,
Shijith Thotton <sthotton@marvell.com>
Subject: Re: [PATCH v2 2/3] event/cnxk: add pause to spinloops
Date: Mon, 8 Jun 2026 10:44:26 -0700 [thread overview]
Message-ID: <20260608104426.6ceb4ad8@phoenix.local> (raw)
In-Reply-To: <CALBAE1PzEtyBzKiKaU83q0OtwRwaCTmqDETsc5NNODDQ9hzauw@mail.gmail.com>
On Mon, 8 Jun 2026 21:19:20 +0530
Jerin Jacob <jerinjacobk@gmail.com> wrote:
> On Mon, Apr 13, 2026 at 10:36 PM Stephen Hemminger
> <stephen@networkplumber.org> wrote:
> >
> > On SMT systems when a spinloop is done without a pause
> > it may cause excessive latency. This problem was found
> > by the fix_empty_spinloops coccinelle script.
> >
> > Signed-off-by: Stephen Hemminger <stephen@networkplumber.org>
>
> rte_pause() translates to YIELD instruction. Since cnxk is an
> integrated SoC and it is a single threaded core, it won't help on
> anything other than adding one instruction bit more latency.
> In general 3/3 devtool is good. Please send a it separate version so
> that 3/3 patches can be merged through the main tree.
It matters if your SOC has SMT where two cores are sharing
and one core is waiting for its partner.
next prev parent reply other threads:[~2026-06-08 17:44 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-01-21 18:05 [RFC 0/3] Add pause to empty spinloops Stephen Hemminger
2026-01-21 18:05 ` [RFC 1/3] net/cnxk: add pause to spinloops Stephen Hemminger
2026-01-21 18:05 ` [RFC 2/3] event/cnxk: " Stephen Hemminger
2026-01-21 21:01 ` Stephen Hemminger
2026-01-21 18:05 ` [RFC 3/3] devtools/cocci: add script to find empty spinloops Stephen Hemminger
2026-04-13 16:45 ` [PATCH v2 0/3] Add pause to empty spin loops Stephen Hemminger
2026-04-13 16:45 ` [PATCH v2 1/3] net/cnxk: add pause to spinloops Stephen Hemminger
2026-04-13 16:45 ` [PATCH v2 2/3] event/cnxk: " Stephen Hemminger
2026-06-08 15:49 ` Jerin Jacob
2026-06-08 17:44 ` Stephen Hemminger [this message]
2026-04-13 16:45 ` [PATCH v2 3/3] devtools/cocci: add script to find empty spinloops Stephen Hemminger
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